a)
0,25a^2-0,04b^2=(0,5a-0,2b)(0,5a+0,2b)
b)
1,44x^2-2,25y^2=(1,2x-1,5y)(1,2x+1,5y)
c)
1,96m^2-2,89n^2=(1,4m-1,7n)(1,4m+1,7n)
d)
\frac{25y^2}{49}-x^2=(\frac{5y}{7}-x)(\frac{5y}{7}+x)
e)
\frac{4y^2}{25}-4z^2=(\frac{2y}{5}-2z)(\frac{2y}{5}+2z)
f)
\frac{9a^2}{16}-\frac{64b^2}{81}=(\frac{3a}{4}-\frac{8b}{9})(\frac{3a}{4}+\frac{8b}{9})